Whilst there are several hundred ornamental onions known, we will simply list the most common garden types.
Flower colours range from white, through pink, deepest red and into various mauve and purple forms.
There are also one or two yellow - but these are not generally as showy or commonly grown as the preceding colours.
Alliums are generally spring or early summer flowering, but their attractive seed heads after flowering can persist through to late autumn - sometimes winter.